A variety of roof shingles are known, which are used, for example, for leakage protection and at the same time for ornamental appearance. For example, U.S. Pat. No. 2,058,578 discloses a thick butt shingle of the felt-based type that is self-spacing and interlocking and is designed to prevent the exposed portion of the shingle from flapping in the wind by aligning non-homologous edges of the shingles with each other. These non-homologous shingle edges comprise a rectangular projection on one edge of the shingle and a recess or indentation on the opposite side. The shingles are then placed whereby the projection of shinge abuts the recess of another shingle, with a second coating layer overlaying a first coat of granular material. The second coat merely provides an additional coat of granular material, and does not serve as an aid in alignment or for any other purpose. Thus, while the shingle disclosed in U.S. Pat. No. 2,058,578 helps to resolve the crooked roof problem, it does not address the problems of shingle cupping or preventing ice damming.
Clearly, such prior art shingles are designed to provide roof protection and aesthetic appearance. However, these same shingles do not effectively resolve the cupping, ice damming, or fly away shingle problems.
The present invention, by contrast with the above-described shingle, is concerned primarily with providing a more durable shingle; specifically, one that prevents: (1) the destructive cupping of the exposed portion of the shingle; (2) leakage induced by ice dam formations; and (3) removal of shingles due to inclement weather conditions. The present invention further provides for each of installation and proper shingle alignment which eliminates the possibility of a crooked roof shingle line.
The present invention contemplates a shingle assembly that is self-gauging, anti-ice damming and double sealed.
The self-gauging system inherent in the present invention serves a multitude of purposes. First of all, the present shingle provides for each of installation because of the automatic gauge built into the shingle. The added gauging material, which is equal in thickness to the shingle, will also prohibit the shingle from cupping upon installation. Second, because of the shingle's self-gauging system, the shingle will be easier to install in a straight line, and thus eliminate the possibility of a crooked roof shingle line. Hence, the shingle will lay flatter on the roof.
The present invention includes a double sealed shingle structure which eliminates ice damming. Ice damming occurs when ice forms on shingles and then travels beneath the shingles and causes leakage due to the inherent expansion of ice. The present invention provides two seal tabs per shingle. In the preferred embodiment, there seal tabs are located at the rear and at the center of the top side of the shingle. In an alternate preferred embodiment, these seal tabs are located at the front and at the center of the back side of the shingle. The extra seal tab, coupled with the double thickness of the shingle (equal thickness in the shingle and gauge piece), prevents the formation of ice beneath the shingles. Furthermore, the extra seal tab prohibits the removal of shingles due to high winds because of added adhesive strength and the added stability provided through the shingle's double thickness.